56. Merge Intervals

Author: TBXark

56. Merge Intervals.md

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+# 56. Merge Intervals
+
+### 2017-03-28
+
+Given a collection of intervals, merge all overlapping intervals.
+
+For example,
+Given `[1,3],[2,6],[8,10],[15,18]`,
+return `[1,6],[8,10],[15,18]`.
+
+
+
+# Solution
+
+```swift
+/**
+ * Definition for an interval.
+ * public class Interval {
+ *   public var start: Int
+ *   public var end: Int
+ *   public init(_ start: Int, _ end: Int) {
+ *     self.start = start
+ *     self.end = end
+ *   }
+ * }
+ */
+class Solution {
+    func merge(_ intervals: [Interval]) -> [Interval] {
+        guard intervals.count > 0 else { return [] }
+        var temp = intervals.sorted { $0.0.start < $0.1.start}
+        var res = [Interval]()
+        var start = temp[0].start
+        var end = temp[0].end
+        for iv in  temp {
+            if iv.start <= end {
+                end = max(iv.end, end)
+            } else {
+                res.append(Interval(start, end))
+                start = iv.start
+                end = iv.end
+            }
+        }
+        res.append(Interval(start, end))
+        return res
+
+    }
+}
+```
+